The present invention is directed toward an improved method and apparatus for insertion of the leads of electronic components into the corresponding holes of a circuit board, wherein an insertion tooling is automatically adjustable to accommodate axial lead components having body portions of varying lengths and wherein this tooling is "lead driving", i.e., drivingly engages the leads rather than the bodies of the components. In particular, the improvement is directed to adaptation of these insertion heads to such component mountings via corresponding circuit board holes which are much more closely spaced than prior art variable spacing "lead driving" insert tooling has been able to handle. Still more particularly, the invention is directed to insertion of axial lead electronic components into spaced holes of a circuit board wherein the center-to-center spacings of the holes are 5 mm. and greater.
Prior art variable center distance machines like those cross-referenced above have not been adaptable to insertion of components into 5 mm. center-to-center hole spacings by lead driving without changing the driver blades for such insertions. Particularly, the prior art insertion apparatus for 5 mm. center-to-center hole spacings has employed tooling which drivingly engages the body of the component or fixed insertion heads, wherein the component lead severing, bending and driving tools incorporated within the insertion head are not relatively adjustable, i.e., such devices have been dedicated to 5 mm. insertion. Hence, an additional insertion head was required for "lead driving" insertion into 5 mm. hole spacings along with larger hole spacings in the same circuit board.
Accordingly, a primary object of the present invention is to provide a "lead driving" insertion method and apparatus which overcomes the above-mentioned necessity for an insertion head dedicated to 5 mm. hole spacings.
It is a further object to provide a method and apparatus for opening and closing insertion tooling relative to a mid-plane in order to accommodate insertion of component leads into circuit board mounting holes of different center distances, while providing closer spacing of the tooling drivers for closer hole spacings such that cooperative structural configurations between the lead drivers and lead formers provides automatic adjustment of the spacing between drivers.
According to the present invention, there is provided an insertion head having a pair of tooling sections which are adjustable, by spreading or closing relative to a midplane, so as to permit a component to be inserted into a board on any desired lead center or center distance (C.D.). The ability of the same insertion head to insert on variable lead centers permits versatility of circuit board design and terminal arrangement, while providing maximum circuit board population density. Still greater density and versatility may be realized by use of the invention to make insertions in 5 mm. hole spacings. In order to provide driver blades similar to those disclosed in the above cross-referenced U.S. Pat. No. Re. 27,968, which will allow closing of the spaced tooling sections sufficiently to handle components having body lengths of 0.150 inches for "lead driving" insertion into 5 mm. hole spacings, it is necessary to reduce the thickness of the driver blades. However, in attempting to mount components on the circuit board via larger hole spacings while using thinner driver blades, misinsertions of particular leads can and do occur during a subsequent clinching operation by kicking an inserted lead out from under the reduced thickness of the driver blade. The instant invention overcomes such difficulties by spacing the driver blades of reduced thickness from the outside formers of such insertion heads when handling insertions in greater hole spacings. In this manner, a reduced thickness blade does not ride upon the radius of a formed lead sufficiently to lose control of such a lead during the subsequent clinching operation.